This summer, I worked with Dr. Jennifer R. Goldschmied in the Sleep Slow Wave Activity Lab. I investigated if changes in cortical excitability, due to slow wave sleep disruption, would impact changes in aggressive, impulsive behavior. Cortical excitability is the strength of response that is generated in cortical neurons following stimulation, and slow wave sleep is the stage of sleep known as deep sleep. Research has found that slow wave sleep influences cortical excitability in a downregulating manner. If slow wave sleep causes a decrease in cortical excitability, then slow wave sleep disruption (SWSD) could cause cortical excitability and synaptic strength to increase during sleep, influencing AIB.​

The participants in this study were taken from a larger overarching study looking at the effects of slow wave sleep on mood disorders in individuals. All of the participants in this study had major depressive disorder, and this was confirmed by a SCID assessment. As a part of the procedure, participants completed two overnight visits, a baseline and disruption visit, one week apart. SWSD only occurred during the disruption visit, while tasks, questionnaires, and TMS protocol were completed during both visits. The tasks and questionnaires used in this study were the Brief Irritability Test (BITe), the  anger subscore of the Profile of Mood State Short Form (POMS, and tbe Go/No-go auditory task; they respectively measured irritability, anger, and impulsivity in the participants. TMS was used to measure the effects of SWSD, using data from motor evoked potentials (MEP), following the overnight visits. MEP was used as a measure of cortical excitability. 

After computing change scores on the MEP, BITe, POMS, and Go/No-go task data in order to look at the impact of SWSD on AIB, it was determined that there was a significant negative correlation between change in MEP and change in the anger subscore of POMS. This suggested that those who showed greater increases in cortical excitability, due to SWSD, showed greater reductions in anger. A significant correlation was not found between cortical excitability and impulsivity. Further research is needed to investigate the impact of SWSD on AIB, specifically in those with major depressive disorder and other mood disorders.